[mythtv-users] Playback problem -- random short pauses

[Zuriel]

I've been having intermittent issues with video playback pausing 
briefly. Pausing for half a second, playing perfectly for 5 seconds and 
just doing that over and over. I've noticed it mostly with LiveTV. I 
haven't finished poking at it and trying to work out what's going on, 
but I may as well throw my two cents in to see if everyone else says 
hey, now that I look at it I'm seeing the same thing. Or someone could 
suggest something to look at next.

I have:

Dedicated backend
Core 2 Duo
4 GB RAM
Four DVB-T tuners
250GB disk (system disk, mysql database)
1TB disk (recordings)
2TB disk (recordings)

Frontend
Atom 
D525/Ion2
2 GB RAM
VDPAU

Both are running master as of a week or 
so ago (v0.25pre-1976-gc77e408).

It originally smelled like a performance problem and after checking the 
network, backend and frontend I've noticed that when my issue is 
occurring, there's something strange 
going on with the backend's system drive. Top shows 50% waiting for IO 
on a dual core CPU and iostat -xk 2 shows under 10% utilization on the 
recording storage drive and 100% on /dev/sda, which is where the root 
partition and mysql database are.

My google-fu has been too weak to find something resembling Win7's 
resource monitor, which can show disk activity per process and which 
files are being accessed how heavily. I might try moving the mysql 
database to a different drive to see if the excessive utilization 
follows it to the new drive.

Thoughts?

Peter
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